Rocky Mountain Tire Center sells 11,000 ?go-cart tires per year. The ordering cost for each order is ?$35?, and the holding cost is 50?% of the purchase price of the tires per year. The purchase price is ?$21 per tire if fewer than 200200 tires are? ordered, ?$17 per tire if 200 or? more, but fewer than 5,000?, tires are? ordered, and ?$13 per tire if 5,000 or more tires are ordered.
a. How many tires should Rocky Mountains tire order each time it time it places an order?
b. What is the total cost of this policy?